Slice for papermaking machines



?'Jan. 6, 1942. M. J. A. M GUIRE ETAL 2,268,840

I SLICE FOR PAPERMAKING MACHINES Filed May 6, 1939 2 Sheets-Sheet l ATTORWEK sheet s sheet 2.

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Filed May 6, 1939 M. J. A. MCGUIRE ET AL SLICE FOR PAPERMAKING MACHINESI 4 M M .1 IIII |-|.I F. Fllillil. w

V a. 5 WHHHH w m Jan. 6, 1942.

Patented Jan. 6, 1942 suon non PAPERMAKING MACHINES Micheal JamesAlphonsus McGuire, Ottawa, n-

tario, and Robert Baptie' Connon, Gatineau,

Quebec, Canada Application May 6, 1939, Serial No. 272,072

. In Canada February 15, 1939 Claims.

This invention relates to paper making machines of the Fourdrinier typeand more particularly to a method and means of maintaining uniformity inthe pulp sheet delivered at various speeds to the wire in such machines.

In present day machines of the type referred to, pulp sheets formed athigh speeds are frequently defective in that they contain longitudinalareas of excessive thickness and/or thinness. Such defects are usuallycaused by a high static head in the head box resulting in a highpressure on and a consequent bulging of the slice which in turn causesdistortion of the slice lip. Currents of pulp flow are frequently set upinthe head box and these infiuence'the uniformity of pulp sheetformation. Moreover, the normal vibration of the slice during operationof the machine at high speeds results in variations in the pulp sheetthickness. The presence of thick and thin streaks in the pulp sheetresults in an incomplete and irregular extraction of Water therefrom bythe vacuum means. The relatively rapid passage of water and air throughthe thin portions prevents the water in the thick portions from beingcompletely extracted, and when the web is transferred from the wire tothe felt it is subject to failure at such, thick portions. Moreover, theuneven moisture content of the web results in an uneven drying thereofand uneven shrinkage. In some cases the latter is sufficient to pull thesheet apart and in other cases to cause the lesser shrunken portions tofold over on themselves and these folds are cut when passing through thecalenders. These defects result in loss due to higher costs for dryingsteam, loss of time due to breakage and production of paper which isbelow standard in quality and finish.

Various means have heretofore been suggested and used for overcomingthese defects but such means have the disadvantage that they are subjectto definite limitations in the formation speed of the pulp sheet.Moreover, such means are usually mounted on or connected to the sliceitself and thus do not take care of defects caused by vibration of theslice.

The object of the present invention is to provide a method and means formaintaining a uniform thickness of pulp sheet regardless of operatingconditions of the machine.

The invention will be described with-reference to the accompanyingdrawings, in which,

Figure 1 is a partial side elevation of a machine embodying theinvention,

Figure 2 is a partial sectional end elevation, and

Figures 3 and 4 are corresponding views including the usual lipadjusting device.

In the drawings, I represents the upper main I plane portion of aninclined slice constituting the front wall of a head box 3 containingpulp stock, 2 a lip member forming the lower portion of the slice, and 4an orifice between the lip and apron being anextension of the floor ofthe head box and through whichthe pulp is delivered onto the wire 5 onthe breast roll 6, all of which are conventional parts of a paper makingmachine. While the lip portion of the slice is shown in the drawings ascurved, it will be understood that the invention is equally applicableto use witha slice the lip portion of which is not curved or flaredoutwardly as shown. Conventional means for specifically adjusting theedge portion of the lip may be provided as shown in Figures 3, and 4 andcomprises a plurality of adjustable rods l8 supported in a framework l9carried by the slice.

In accordance with the invention, an 'I-beam or the like 1 is mounted,independently of the slice, on supports 8 carried by the main frame 9 ofthe paper machine on either sideof the wire. -As shown, the beam 1extends transversely of the machine above the wire and a short distancein front of the slice, the beam being angularly positioned so that itsflange faces are parallel to the inclined slice face.

A series of independently adjustable devices are provided between theslice and the adjacent flange of the I-beam. Such adjustable devices orconnections may take various 'forms as, .for instance, a wedge or cammember or a hydraulic jack or as in the preferred form shown, an eyebolt I0 is mounted on the I-beam flange and a bolt ll having a forkedhead is fitted thereto by means of pin I2. A second forked-head bolt I3is fitted by means of pin 14 to a web, gusset or the like IS on theslice adjacent the point where the lip begins to curve outwardly. One ofthe bolts II and I3 has a right hand thread and the other a left handthread. An elongated nut [6 having threads at either end correspondingto the threads of bolts l I and I3 forms a connection between suchbolts. A lock nut ll may also be provided.

In operation, when distortions occur in the orifice 4, one or more ofthe nuts l6, as required, are adjusted to move the slice inwardly oroutwardly at the points of connection an amount suflicient to remove thedistortions in the orifice.

It will be observed that the forces exerted by the adjustable devices ofthe present invention are applied along aline spaced above the loweredge of the slice and lying within the zone of maximum static headpressure of pulp stock on the slice. The latter zone comprises a bandextending transversely of the slice immediately above the point at whichthe static head pressure on the slice is somewhat reduced by virtue ofthe outward flow of the pulp through the orifice 4. The band may varysomewhat with size of slice and depth of pulp stock. As shown the lineof application of the adjusting forces is also in the plane of the mainportion l and the forces are applied in a direction perpendicular tosuch apron, a head box containing pulp stock and a wire, said head boxhaving,its front wall conforces are applied within the proper zone foran effective and accurate adjustment of the slice. If adjustment of theslice were made a substantial distance above this zone, there would be apossibility of distortion in the slice below the adjustment line whichcould not be overcome. The usual adjustment of the slice lip by means ofthe rods l8 may be made to control minor variations in the pulp fiow.

Distortions caused by operating vibrations in the slice are alsoeliminated by the adjustable devices since they are carried by a memberwhich is supported on the main frame entirely independent of the slice.

There is thus provided a method and means for accurately maintaining thedelivery to the wire of a pulp sheet of uniform thickness regardless ofoperating conditions ofthe machine.

We claim: a

1. In a paper-making machine having an apron, a head box containing pulpstock and a. wire, said head box having its front wall constituting aslice and a pulp stock orifice between the lower edge of said front walland said apron whereby a pulp sheet may be delivered through the orificeonto the wire, means for maintaining uniform thickness in said sheetcomprising .a beam extending transversely of said front wall in parallelrelation thereto, supports for said front wall extending therefrom tosaid beam, said supports being anchored to the front wall at pointsspaced above the lower marginal portion thereof adjacent the top of thelip of the slice and lying within the zone of maximum static head pres-.sure of pulp stock on the wall, and means for independently adjustingthe length of each of said supports to apply adjusting forces to saidfront wall at said points and thereby maintain said lower edge a uniformdistance from said apron.

2. In a paper-making machine having an apron, a head box containing pulpstock and a wire, said head box having its front wall constituting aslice and the lower edge portion of the front wall constituting a, slicelip and a pulp stock orifice between the lower edge of the front walland said apron whereby a pulp sheet may be delivered through the orificeonto the wire, means for maintaining uniform thickness in said sheetcomprising a rigid member extending in adjoining relation to said frontwall, supports for said front wall extending therefrom to said rigidmember, said supports being anchored to the front wall at points spacedabove the lower marginal portion thereof adjacent the top of the slicelip and lying within the zone of maximum static head pressure of pulpstock on the wall, and means for independently adjusting the length ofeach of said supports to apply adjusting forces to said front wall atsaid points and thereby maintain said lower edge a uniform distance fromsaid apron.

stituting a slice, the lower edge portion of said front wall beingoutwardly flared and constituting a slice lip, and a pulp stock orificebetween the lower edge of the front wall and said apron whereby a pulpsheet may be delivered through the orifice onto the wire, means formaintaining uniform thickness in said sheet comprising a rigid memberextending in adjoining relation to said front wall, supports for saidfront wall extending therefrom to said. rigid member, said supportsbeing anchored to the front wall at points spaced above the lowermarginal portion thereof adjacent the top of the slice lip and lyingwithin the zone of maximum static head pressure of pulp stock on thewall, and means for independently adjusting the length of each of saidsupports to apply adjusting forces to said front wall at said points andthereby maintain said lower edge a uniform distance from said apron.

4. In a paper-making machine having an apron, a head box containing pulpstock and a wire, said head box having its front wall constituting aslice and the lower edge portion of the front wall constituting a slicelip and a pulp stock orifice between the lower edge of the front walland said apron whereby a pulp sheet may be delivered throughthe orificeonto the wire, lipengaging means for adjusting-the depth of saidorifice, and means for maintaining uniform thickness in said sheetcomprising a rigid member extending in adjoining relation to said frontwall, supports for said front wall extending therefrom to said rigidmember, said supports being anchored to the front wall at points spacedabove the lower marginal portion thereof adjacent the top of the slicelip and lying within the zone of maximum static head pressure of pulpstock on the wall, and means for independently adjusting the length ofeach of saidsupports to apply ad'- justing forces to said front wall atsaid points and thereby maintain said lower edge a uniform distance fromsaid apron.

5. In a paper-making machine having an apron, a head box containing pulpstock and a wire, said head box having its front wall constituting aslice, the lower edge portion of said front wall being outwardly flaredand constituting a slice lip, and a pulp stock orifice between the loweredge of the front wall and said apron whereby a pulp sheet may bedelivered through the orifice onto the wire, lip-engaging means foradjusting the depth of said orifice, and means for maintaining uniformthickness in said sheet comprising a rigid member extending in adjoiningrelation to said front wall, supports for said front wall extendingtherefrom to said rigid member, said supports being anchored to thefront wall at points spaced above the lower marginal portion thereofadjacent the top of the slice lip and lying within the zone of maximumstatic head pressure of pulp stock on the wall, and means 3. In apaper-making machine having an ROBERT BAPTIE CONNON.

